Oil recovery device



Feb 25, 1936.

N. M. SMALL ET AL 2,032,230

OIL RECOVERY DEVICE Filed July 31, 1953 w N TTYTT .MMA. ==T====== J Q X N L L J awe/FM NormanMsmali Eancid Shenfan Patented Feb. 25, 1936 UNITED STATES OIL RECOVERY DEVICE N orman Mi Small and Francis Shenton, Waynesboro, Pa., assgnors to Frick Company, Waynesboro, Pa., a corporation of Pennsylvania Application July 31, 1933, Serial No. 683,087

. 16 Claims.

This invention relates to method and means for removing oil or other impurities from a volatile liquid. While not limited to use with a refrigerating system the invention does have particular application to the removal of oil from the liquid refrigerant in a refrigerating system.

An object .of the invention therefore is'to provide a means and method of removing oil from a more volatile liquid and to carry out the process'whilethe liquid is being circulated in performing its regular function in the system in which it is an operative element.

Referring to the accompanying drawing on which similar reference characters indicate similar parts,

v Thesingle figure is an elevation of the invention applied to a refrigerating system.

In systems where fluids are circulated, such a in refrigerating plants, lubricating-oil from the compressor isfrequently distributed through the piping of the system. The presence of oil on the lower eificiency and impairs operation of the plant. In some cases this oil may be drained directly out of the system but in other instances,

especially where it is soluble in the refrigerant or where it is lighter than the refrigerant and hence floating on the top of the refrigerant, draining out of the oil is not er'dcient.

In our invention we remove oilfrom any portion of the system and return it to the crank case or compressor or to any other vessel from which it may be drained out of the system. We accomplish this by tamng oil or a mixture of oil and refrigerant from such points in the system as where the oil concentration is likely to be high- 7 est and pass this oil through a heat exchanger where the mixture of oil and some refrigerant present in the oil is heated. The refrigerant gas developed bythe heating is delivered to the suc- 'tion of the compressor after separating it from liquid refrigerant is delivered through pipe l3" through vessel 23 and through expansion valve it into an evaporator l5. Liquid refrigerant from some portion of the evaporator I5 is drawn out through pipe I6 by a pump 3| and forced by the pump through line I! through oil separator 2-4! and pipe J9 back into the evaporator; The oil separator 2| containsa plurality of battle plates 26 which plates or screens assist in freeing the refrigerant from the oil. In the system as illustrated the oil is lighter than the liquid refrigerant and hence floats to the top of the vessel 2|.

such refrigerant as may be mixed with it is ex panded through an expansion valve 29 into a coil 22 within the vessel 23 where the oil and refrigerant mixed with it is raised in temperature by the hot liquid refrigerant from the line 13. This heating evaporates the refrigerant in the oil and the oil and the gaseous refrigerant pass off through the line 24 into the line 20 through which line the oil and gas pass into an oil separator 25.

Here the oil is separated from the gaseous refrigerant and drops to the bottom of. tank 25 from which point it passes through line 27 to the crank case 28 of the compressor. The gaseous refrigerant mixed with the gas returning through the line 20 is delivered into the suction of the compressor I 0. The expansion valve 29 is operated by a thermostat 30 which is placed in heat exchange relation with the suction line 2 5 so that the valve 2% opens only when the pipe 2% is relatively warm and closes when the pipe 2 is cold, thus automatically feeding oil or refrigerant to coil 22 and preventing liquid refrigerant from passingto the suction line 20 to the compressor While the automatically operated valve 29 isfound to be a convenience it is not absolutely essential, as any kind of expansion valve may be used'in place of the valve 29. If the oil in the oil separating chamber 2| is heavier than the refrigerant in this chamber the line passing to valve 29 will be positioned near the bottom of the chamber instead of at the top as shown in the form illustrated. In the form illustrated a pump is shown for circulating the refrigerant from and back to the evaporator 15. This develops a pressure upon the separated oil and refrigerant in the chamber 2| to force it through the coil 22 and pipe 24 into the suction line 20. If the points from which the oil is to be moved are sufficiently elevated above the compressor the flow of oil' can be controlled by gravity and the pump may be found unnecessary. When operating on the low side of the refrigerating sys tem a pump may be used to circulate the oil and the refrigerant mixed with it through the coil 22 without use of the pump 3! for circulating refrigerant from and back to evaporator l5. Again-attention is called to the fact that, while, for the purpose of convenience, the system has been defined in its use with a refrigerating system; in the removal of oil from the refrigerant, the invention is not limited to such a system or to the removal of oil. Other impurities such as water or brine may be present and the system is Oil from the top of the vessel 2| together with enough tocover the removal of oil or other liquid impurities from any liquidin which it is mixed and from which it is desired to have it removed; 5

;It will be obvious to those skilled inthe art that various changes may be made in ouridevice without departing from the spirit of the invention and therefore we do not limit ourselves to what is shown in'the drawing and described in livering the 'oil te some portion of the compressor for lubricating said compressor and for delivering the vaporized refrigerant to the suction of the compressor, substantially as set forth.-

2. In a refrigerating system an oil separator? comprising means for withdrawing oil from a portion of the system wherein oil is in a concentrate'l form, means for vaporizing the refrigerant from the oil, and means controlled by the temperature of the vaporized oil and refrigerant mixture for controlling the passage of the oil and refrigerant through the heating system,

substantially asset forth. i

3. In amefrigerating system, a compressor, a condenser, an evaporator, an oil separator, means i for circulating oil laden refrigerant from said evaporator through said separator and'directly back to said evaporator, means for drawing off oil from said separator, meansefor evaporating refrigerant therefrom and delivering said evaporated refrigerant to the suction of the compressor and the oil to the crank rase of said compressor, substantially as set forth.

4. That imprnvement gin the art of refrigeration which comprises withdrawing a quantity of oil and refrigerant from an accumulation in the system, reducing its pressure,- and controlling said withdrawal in accordance with the temperature of fluid withdrawn.

5. That imprpvement in the art of refrigeration which comprises withdrawing oil and refrigerant mixture a large portion of which isoil from; an accgmulation in the system, and stopping said withdrawal when the decrease of the proportionof oil reaches a predetermined amount. K

6. That improvement in the art of refrigera= tion which comprises withdrawing a mixture the greater portion of which is oil and the lesser portion of which is refrigerant from an accumulation in the system, and reducing said withdrawal when the withdrawn mixture becomes substantially all refrigerant.

7. That improvement in the art of refrigeration which comprises removing oil and refrigerant from a body of oil and refrigerant and controlling such removal in accordance with the quantity of refrigerant withdrawn.

8. That improvement in the art of refrigeration which comprises removing oil and refriggerant from an accumulation in a refrigerating system, and controlling such removal in accordance with the ratio of oil and refrigerant with drawn from the accumulation;

9. That improvement in the art of refrigeration wherein a liquid refrigerant is evaporated, which comprises withdrawing oh and refrigerant from an accumulation in a sys'gem and utilizing the refrigerant withdrawn to cool the refrigeraant supply prior to evaporation. r

10. That improvement in the art of refrigeration comprising removing oil from an accumulation and returning it to a place to be used and controlling said removal by the evaporative temperature of the mixture of oil and refrigerant removed.

11. That improvement in the art of refrigeration comprising removing oil from an accumulation and returning it to a place to be used and controlling said removal by the evaporative tenrperature of the mixture of oil and refrigerant, and passing said mixture in heat exchange relaition with incoming liquid refrigerant from- 9. source of supply.

12. in a refrigerating system including com;-

; pressing, condensing and evaporating means,

means for precooling a mixture of oil and liquid from the condenser by liquid refrigerant withdrawn from an accumulation in the system, and

means for controlling the flow of said mixture through the precooling means in accordance with the evaporation of liquid frorrr the mixture passing through the precooler. i

13. Removing oil and refrigerant from an evaporative system, subjecting it to heat exchange with freshly condensed refrigerant, reducing the pressure of the withdrawn fluid, and controlling said removal by the temperature of the mixture of oil and refrigerant.

1.4. That improvement in the art of refrigeration comprising removing oil and refrigerant from a compression system, and returning the oil to the crankcase of the compressor for reuse in the system, reducing the pressure of the withdrawn fluid, and controlling said removal by the temperature e f the mixture in heat exchange relation with liquid from the condenser.

15. Ina refrigerating system containing a refrigerant and a lubricant, means for accumulating a body of the refrigerant and lubricant,

means for withdrawing refrigerant and lubricant from such accumulation, and means for varying the amount ofwithdrawn liquid in proportion to the amount of refrigerant therein and means for passing the withdrawn liquid in heat exchange relation with refrigerant at a warmer temperature in the system for cooling the same.

16. In a refrigerating system containing a refrigerant and a lubricant, means for accumulating a body of the refrigerant and lubricant, means for withdrawing refrigerant and lubricant from such accumulation, and means for varying the amount. of withdrawn liquid in proportion to the amount of refrigerant therein, means for passing the withdrawn liquid in heat exchange relation with refrigerant at a warmer temperature in the system for cooling the same, and means for discharging the withdrawn liquid into the suction line of the system. I

NORMAN M. SMALL. FRANCIS SHENTON. 

